function tostring(obj) {
    var str = '';
    for (var key in obj) {
        str += `${key}=${obj[key]}&`
    }
    return str.slice(0,str.length - 1)
}

function ajax(medthod, url, paparms) {
    return new Promise((resolve, reject) =>{
        var xhr = new XMLHttpRequest();
        xhr.open(medthod, medthod == 'get' ? url + "?" + tostring(paparms) : url);
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4) {
                resolve(JSON.parse(xhr.responseText))
            }
        }
        xhr.setRequestHeader('content-type', 'application/x-www-form-urlencoded');
        xhr.send(medthod == 'get' ? null : tostring(paparms));
    })
}